Control device for influencing the driving dynamics of four-wheel vehicles
AssigneeDaimlerChrysler AG
InventorJochen Goetz
Life of this patent
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Abstract
In a control device for influencing the driving dynamics of four-wheel vehicles, the vehicle lengthwise speed and the steering angle are introduced as input signals and control signals are generated that act on positioning devices for adjusting the vehicle wheels. In order to set and adjust the transverse dynamic properties of a vehicle with a low cost of construction in normal driving, for setting a desired driving behavior, target values may be specified for the steering ratio, the self-steering gradient, and the float angle gradient as set signals from which steady-state additional trail angles can be determined which can be supplied as control signals to the positioning devices.
Claims14
A control device for adjusting driving dynamics of a four wheel vehicle, comprising:
- inputs for receiving first and second signals indicative of vehicle longitudinal speed vx and steering angle δ, respectively;
- means coupled to receive said first and second signals, for generating control signals for controlling vehicle wheels of said vehicle;
- and
- positioning devices for controlling said vehicle wheels in response to said control signals;
- wherein
- said control device has additional inputs for receiving selectable target values for a steering ratio ilz, a self steering gradient Egz and a float angle gradient SGz as set signals for setting a desired driving behavior;
- transverse acceleration of the vehicle corresponds to the relationship
- ay=δ1/ilz*vx2/(vx2*Egz+1r),
- where 1r represents a wheelbase of the vehicle;
- a steady-state additional float angle βs corresponds to the relationship
- βs=ay*(SGB−SGz)
- rear and front steady-state trail angles δzhs, δzvs correspond to the relationship
- δzhs=βs
- δzvs=βs+δzels
- with the steady-state additional self-steering angle
- δzels=δ1/ilz*((vx2*EGB+1r)/(vx2*EGz+1r))−δ1/ilB
- where ilB is a known basic value of the steering ratio, EGB is a known basic value of the self-steering gradient, and the control signals that can be supplied to the positioning devices represent steady-state additional rear and front trail angles δzhd, δzvd.
Dependencies are inferred from the claim text.